sim/igen/gen-semantics.c - third_party/binutils-gdb - Git at Google

 /* The IGEN simulator generator for GDB, the GNU Debugger.

    Copyright 2002-2024 Free Software Foundation, Inc.

    Contributed by Andrew Cagney.

    This file is part of GDB.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */


 #include "misc.h"
 #include "lf.h"
 #include "table.h"
 #include "filter.h"
 #include "igen.h"

 #include "ld-insn.h"
 #include "ld-decode.h"

 #include "gen.h"

 #include "gen-semantics.h"
 #include "gen-icache.h"
 #include "gen-idecode.h"


 static void
 print_semantic_function_header (lf *file,
 				const char *basename,
 				const char *format_name,
 				const opcode_bits *expanded_bits,
 				int is_function_definition,
 				int nr_prefetched_words)
 {
   int indent;
   lf_printf (file, "\n");
   lf_print__function_type_function (file, print_semantic_function_type,
 				    "EXTERN_SEMANTICS",
 				    (is_function_definition ? "\n" : " "));
   indent = print_function_name (file,
 				basename,
 				format_name,
 				NULL,
 				expanded_bits,
 				function_name_prefix_semantics);
   if (is_function_definition)
     {
       indent += lf_printf (file, " ");
       lf_indent (file, +indent);
     }
   else
     {
       lf_printf (file, "\n");
     }
   lf_printf (file, "(");
   lf_indent (file, +1);
   print_semantic_function_formal (file, nr_prefetched_words);
   lf_indent (file, -1);
   lf_printf (file, ")");
   if (is_function_definition)
     {
       lf_indent (file, -indent);
     }
   else
     {
       lf_printf (file, ";");
     }
   lf_printf (file, "\n");
 }

 void
 print_semantic_declaration (lf *file,
 			    const insn_entry *insn,
 			    const opcode_bits *expanded_bits,
 			    const insn_opcodes *opcodes,
 			    int nr_prefetched_words)
 {
   print_semantic_function_header (file,
 				  insn->name,
 				  insn->format_name,
 				  expanded_bits,
 				  0 /* is not function definition */ ,
 				  nr_prefetched_words);
 }


 /* generate the semantics.c file */


 void
 print_idecode_invalid (lf *file, const char *result, invalid_type type)
 {
   const char *name;
   switch (type)
     {
     default:
       name = "unknown";
       break;
     case invalid_illegal:
       name = "illegal";
       break;
     case invalid_fp_unavailable:
       name = "fp_unavailable";
       break;
     case invalid_wrong_slot:
       name = "wrong_slot";
       break;
     }
   if (options.gen.code == generate_jumps)
     {
       lf_printf (file, "goto %s_%s;\n",
 		 (options.gen.icache ? "icache" : "semantic"), name);
     }
   else if (options.gen.icache)
     {
       lf_printf (file, "%s %sicache_%s (", result,
 		 options.module.global.prefix.l, name);
       print_icache_function_actual (file, 0);
       lf_printf (file, ");\n");
     }
   else
     {
       lf_printf (file, "%s %ssemantic_%s (", result,
 		 options.module.global.prefix.l, name);
       print_semantic_function_actual (file, 0);
       lf_printf (file, ");\n");
     }
 }


 void
 print_semantic_body (lf *file,
 		     const insn_entry *instruction,
 		     const opcode_bits *expanded_bits,
 		     const insn_opcodes *opcodes)
 {
   /* validate the instruction, if a cache this has already been done */
   if (!options.gen.icache)
     {
       print_idecode_validate (file, instruction, opcodes);
     }

   print_itrace (file, instruction, 0 /*put_value_in_cache */ );

   /* generate the instruction profile call - this is delayed until
      after the instruction has been verified.  The count macro
      generated is prefixed by ITABLE_PREFIX */
   {
     lf_printf (file, "\n");
     lf_indent_suppress (file);
     lf_printf (file, "#if defined (%sPROFILE_COUNT_INSN)\n",
 	       options.module.itable.prefix.u);
     lf_printf (file, "%sPROFILE_COUNT_INSN (CPU, CIA, MY_INDEX);\n",
 	       options.module.itable.prefix.u);
     lf_indent_suppress (file);
     lf_printf (file, "#endif\n");
   }

   /* generate the model call - this is delayed until after the
      instruction has been verified */
   {
     lf_printf (file, "\n");
     lf_indent_suppress (file);
     lf_printf (file, "#if defined (WITH_MON)\n");
     lf_printf (file, "/* monitoring: */\n");
     lf_printf (file, "if (WITH_MON & MONITOR_INSTRUCTION_ISSUE)\n");
     lf_printf (file, "  mon_issue (");
     print_function_name (file,
 			 instruction->name,
 			 instruction->format_name,
 			 NULL, NULL, function_name_prefix_itable);
     lf_printf (file, ", cpu, cia);\n");
     lf_indent_suppress (file);
     lf_printf (file, "#endif\n");
     lf_printf (file, "\n");
   }

   /* determine the new instruction address */
   {
     lf_printf (file, "/* keep the next instruction address handy */\n");
     if (options.gen.nia == nia_is_invalid)
       {
 	lf_printf (file, "nia = %sINVALID_INSTRUCTION_ADDRESS;\n",
 		   options.module.global.prefix.u);
       }
     else
       {
 	int nr_immeds = instruction->nr_words - 1;
 	if (options.gen.delayed_branch)
 	  {
 	    if (nr_immeds > 0)
 	      {
 		lf_printf (file, "cia.dp += %d * %d; %s\n",
 			   options.insn_bit_size / 8, nr_immeds,
 			   "/* skip dp immeds */");
 	      }
 	    lf_printf (file, "nia.ip = cia.dp; %s\n",
 		       "/* instruction pointer */");
 	    lf_printf (file, "nia.dp = cia.dp + %d; %s\n",
 		       options.insn_bit_size / 8,
 		       "/* delayed-slot pointer */");
 	  }
 	else
 	  {
 	    if (nr_immeds > 0)
 	      {
 		lf_printf (file, "nia = cia + %d * (%d + 1); %s\n",
 			   options.insn_bit_size / 8, nr_immeds,
 			   "/* skip immeds as well */");

 	      }
 	    else
 	      {
 		lf_printf (file, "nia = cia + %d;\n",
 			   options.insn_bit_size / 8);
 	      }
 	  }
       }
   }

   /* if conditional, generate code to verify that the instruction
      should be issued */
   if (filter_is_member (instruction->options, "c")
       || options.gen.conditional_issue)
     {
       lf_printf (file, "\n");
       lf_printf (file, "/* execute only if conditional passes */\n");
       lf_printf (file, "if (IS_CONDITION_OK)\n");
       lf_printf (file, "  {\n");
       lf_indent (file, +4);
       /* FIXME - need to log a conditional failure */
     }

   /* Architecture expects a REG to be zero.  Instead of having to
      check every read to see if it is refering to that REG just zap it
      at the start of every instruction */
   if (options.gen.zero_reg)
     {
       lf_printf (file, "\n");
       lf_printf (file, "/* Architecture expects REG to be zero */\n");
       lf_printf (file, "GPR_CLEAR(%d);\n", options.gen.zero_reg_nr);
     }

   /* generate the code (or at least something */
   lf_printf (file, "\n");
   lf_printf (file, "/* semantics: */\n");
   if (instruction->code != NULL)
     {
       /* true code */
       lf_printf (file, "{\n");
       /* NB: Do not indent the code.  If the .igen source files cause a compiler
 	 warning, the diagnostics can read the line from the original source,
 	 but use column offsets from the generated files, causing columns to be
 	 misaligned.  It makes the generated code slightly more difficult to
 	 read, but accurate compiler diagnostics relative to the original source
 	 are more important here.
       lf_indent (file, +2); */
       lf_print__line_ref (file, instruction->code->line);
       table_print_code (file, instruction->code);
       /* NB: Disabled -- see above.
       lf_indent (file, -2); */
       lf_printf (file, "}\n");
       lf_print__internal_ref (file);
     }
   else if (filter_is_member (instruction->options, "nop"))
     {
       lf_print__internal_ref (file);
     }
   else
     {
       const char *prefix = "sim_engine_abort (";
       int indent = strlen (prefix);
       /* abort so it is implemented now */
       lf_print__line_ref (file, instruction->line);
       lf_printf (file, "%sSD, CPU, cia, \\\n", prefix);
       lf_indent (file, +indent);
       lf_printf (file, "\"%s:%d:0x%%08lx:%%s unimplemented\\n\", \\\n",
 		 filter_filename (instruction->line->file_name),
 		 instruction->line->line_nr);
       lf_printf (file, "(long) CIA, \\\n");
       lf_printf (file, "%sitable[MY_INDEX].name);\n",
 		 options.module.itable.prefix.l);
       lf_indent (file, -indent);
       lf_print__internal_ref (file);
     }

   /* Close off the conditional execution */
   if (filter_is_member (instruction->options, "c")
       || options.gen.conditional_issue)
     {
       lf_indent (file, -4);
       lf_printf (file, "  }\n");
     }
 }

 static void
 print_c_semantic (lf *file,
 		  const insn_entry *instruction,
 		  const opcode_bits *expanded_bits,
 		  const insn_opcodes *opcodes,
 		  cache_entry *cache_rules,
 		  int nr_prefetched_words)
 {

   lf_printf (file, "{\n");
   lf_indent (file, +2);

   print_my_defines (file,
 		    instruction->name,
 		    instruction->format_name, expanded_bits);
   lf_printf (file, "\n");
   print_icache_body (file,
 		     instruction,
 		     expanded_bits,
 		     cache_rules,
 		     (options.gen.direct_access
 		      ? define_variables
 		      : declare_variables),
 		     (options.gen.icache
 		      ? get_values_from_icache
 		      : do_not_use_icache), nr_prefetched_words);

   lf_printf (file, "%sinstruction_address nia;\n",
 	     options.module.global.prefix.l);
   print_semantic_body (file, instruction, expanded_bits, opcodes);
   lf_printf (file, "return nia;\n");

   /* generate something to clean up any #defines created for the cache */
   if (options.gen.direct_access)
     {
       print_icache_body (file,
 			 instruction,
 			 expanded_bits,
 			 cache_rules,
 			 undef_variables,
 			 (options.gen.icache
 			  ? get_values_from_icache
 			  : do_not_use_icache), nr_prefetched_words);
     }

   lf_indent (file, -2);
   lf_printf (file, "}\n");
 }

 static void
 print_c_semantic_function (lf *file,
 			   const insn_entry *instruction,
 			   const opcode_bits *expanded_bits,
 			   const insn_opcodes *opcodes,
 			   cache_entry *cache_rules,
 			   int nr_prefetched_words)
 {
   /* build the semantic routine to execute the instruction */
   print_semantic_function_header (file,
 				  instruction->name,
 				  instruction->format_name,
 				  expanded_bits,
 				  1 /*is-function-definition */ ,
 				  nr_prefetched_words);
   print_c_semantic (file,
 		    instruction,
 		    expanded_bits, opcodes, cache_rules, nr_prefetched_words);
 }

 void
 print_semantic_definition (lf *file,
 			   const insn_entry *insn,
 			   const opcode_bits *expanded_bits,
 			   const insn_opcodes *opcodes,
 			   cache_entry *cache_rules,
 			   int nr_prefetched_words)
 {
   print_c_semantic_function (file,
 			     insn,
 			     expanded_bits,
 			     opcodes, cache_rules, nr_prefetched_words);
 }
	/* The IGEN simulator generator for GDB, the GNU Debugger.

	Copyright 2002-2024 Free Software Foundation, Inc.

	Contributed by Andrew Cagney.

	This file is part of GDB.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */



	#include "misc.h"
	#include "lf.h"
	#include "table.h"
	#include "filter.h"
	#include "igen.h"

	#include "ld-insn.h"
	#include "ld-decode.h"

	#include "gen.h"

	#include "gen-semantics.h"
	#include "gen-icache.h"
	#include "gen-idecode.h"


	static void
	print_semantic_function_header (lf *file,
	const char *basename,
	const char *format_name,
	const opcode_bits *expanded_bits,
	int is_function_definition,
	int nr_prefetched_words)
	{
	int indent;
	lf_printf (file, "\n");
	lf_print__function_type_function (file, print_semantic_function_type,
	"EXTERN_SEMANTICS",
	(is_function_definition ? "\n" : " "));
	indent = print_function_name (file,
	basename,
	format_name,
	NULL,
	expanded_bits,
	function_name_prefix_semantics);
	if (is_function_definition)
	{
	indent += lf_printf (file, " ");
	lf_indent (file, +indent);
	}
	else
	{
	lf_printf (file, "\n");
	}
	lf_printf (file, "(");
	lf_indent (file, +1);
	print_semantic_function_formal (file, nr_prefetched_words);
	lf_indent (file, -1);
	lf_printf (file, ")");
	if (is_function_definition)
	{
	lf_indent (file, -indent);
	}
	else
	{
	lf_printf (file, ";");
	}
	lf_printf (file, "\n");
	}

	void
	print_semantic_declaration (lf *file,
	const insn_entry *insn,
	const opcode_bits *expanded_bits,
	const insn_opcodes *opcodes,
	int nr_prefetched_words)
	{
	print_semantic_function_header (file,
	insn->name,
	insn->format_name,
	expanded_bits,
	0 /* is not function definition */ ,
	nr_prefetched_words);
	}



	/* generate the semantics.c file */


	void
	print_idecode_invalid (lf file, const char result, invalid_type type)
	{
	const char *name;
	switch (type)
	{
	default:
	name = "unknown";
	break;
	case invalid_illegal:
	name = "illegal";
	break;
	case invalid_fp_unavailable:
	name = "fp_unavailable";
	break;
	case invalid_wrong_slot:
	name = "wrong_slot";
	break;
	}
	if (options.gen.code == generate_jumps)
	{
	lf_printf (file, "goto %s_%s;\n",
	(options.gen.icache ? "icache" : "semantic"), name);
	}
	else if (options.gen.icache)
	{
	lf_printf (file, "%s %sicache_%s (", result,
	options.module.global.prefix.l, name);
	print_icache_function_actual (file, 0);
	lf_printf (file, ");\n");
	}
	else
	{
	lf_printf (file, "%s %ssemantic_%s (", result,
	options.module.global.prefix.l, name);
	print_semantic_function_actual (file, 0);
	lf_printf (file, ");\n");
	}
	}


	void
	print_semantic_body (lf *file,
	const insn_entry *instruction,
	const opcode_bits *expanded_bits,
	const insn_opcodes *opcodes)
	{
	/* validate the instruction, if a cache this has already been done */
	if (!options.gen.icache)
	{
	print_idecode_validate (file, instruction, opcodes);
	}

	print_itrace (file, instruction, 0 /put_value_in_cache / );

	/* generate the instruction profile call - this is delayed until
	after the instruction has been verified. The count macro
	generated is prefixed by ITABLE_PREFIX */
	{
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined (%sPROFILE_COUNT_INSN)\n",
	options.module.itable.prefix.u);
	lf_printf (file, "%sPROFILE_COUNT_INSN (CPU, CIA, MY_INDEX);\n",
	options.module.itable.prefix.u);
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
	}

	/* generate the model call - this is delayed until after the
	instruction has been verified */
	{
	lf_printf (file, "\n");
	lf_indent_suppress (file);
	lf_printf (file, "#if defined (WITH_MON)\n");
	lf_printf (file, "/* monitoring: */\n");
	lf_printf (file, "if (WITH_MON & MONITOR_INSTRUCTION_ISSUE)\n");
	lf_printf (file, " mon_issue (");
	print_function_name (file,
	instruction->name,
	instruction->format_name,
	NULL, NULL, function_name_prefix_itable);
	lf_printf (file, ", cpu, cia);\n");
	lf_indent_suppress (file);
	lf_printf (file, "#endif\n");
	lf_printf (file, "\n");
	}

	/* determine the new instruction address */
	{
	lf_printf (file, "/* keep the next instruction address handy */\n");
	if (options.gen.nia == nia_is_invalid)
	{
	lf_printf (file, "nia = %sINVALID_INSTRUCTION_ADDRESS;\n",
	options.module.global.prefix.u);
	}
	else
	{
	int nr_immeds = instruction->nr_words - 1;
	if (options.gen.delayed_branch)
	{
	if (nr_immeds > 0)
	{
	lf_printf (file, "cia.dp += %d * %d; %s\n",
	options.insn_bit_size / 8, nr_immeds,
	"/* skip dp immeds */");
	}
	lf_printf (file, "nia.ip = cia.dp; %s\n",
	"/* instruction pointer */");
	lf_printf (file, "nia.dp = cia.dp + %d; %s\n",
	options.insn_bit_size / 8,
	"/* delayed-slot pointer */");
	}
	else
	{
	if (nr_immeds > 0)
	{
	lf_printf (file, "nia = cia + %d * (%d + 1); %s\n",
	options.insn_bit_size / 8, nr_immeds,
	"/* skip immeds as well */");

	}
	else
	{
	lf_printf (file, "nia = cia + %d;\n",
	options.insn_bit_size / 8);
	}
	}
	}
	}

	/* if conditional, generate code to verify that the instruction
	should be issued */
	if (filter_is_member (instruction->options, "c")
	\|\| options.gen.conditional_issue)
	{
	lf_printf (file, "\n");
	lf_printf (file, "/* execute only if conditional passes */\n");
	lf_printf (file, "if (IS_CONDITION_OK)\n");
	lf_printf (file, " {\n");
	lf_indent (file, +4);
	/* FIXME - need to log a conditional failure */
	}

	/* Architecture expects a REG to be zero. Instead of having to
	check every read to see if it is refering to that REG just zap it
	at the start of every instruction */
	if (options.gen.zero_reg)
	{
	lf_printf (file, "\n");
	lf_printf (file, "/* Architecture expects REG to be zero */\n");
	lf_printf (file, "GPR_CLEAR(%d);\n", options.gen.zero_reg_nr);
	}

	/* generate the code (or at least something */
	lf_printf (file, "\n");
	lf_printf (file, "/* semantics: */\n");
	if (instruction->code != NULL)
	{
	/* true code */
	lf_printf (file, "{\n");
	/* NB: Do not indent the code. If the .igen source files cause a compiler
	warning, the diagnostics can read the line from the original source,
	but use column offsets from the generated files, causing columns to be
	misaligned. It makes the generated code slightly more difficult to
	read, but accurate compiler diagnostics relative to the original source
	are more important here.
	lf_indent (file, +2); */
	lf_print__line_ref (file, instruction->code->line);
	table_print_code (file, instruction->code);
	/* NB: Disabled -- see above.
	lf_indent (file, -2); */
	lf_printf (file, "}\n");
	lf_print__internal_ref (file);
	}
	else if (filter_is_member (instruction->options, "nop"))
	{
	lf_print__internal_ref (file);
	}
	else
	{
	const char *prefix = "sim_engine_abort (";
	int indent = strlen (prefix);
	/* abort so it is implemented now */
	lf_print__line_ref (file, instruction->line);
	lf_printf (file, "%sSD, CPU, cia, \\\n", prefix);
	lf_indent (file, +indent);
	lf_printf (file, "\"%s:%d:0x%%08lx:%%s unimplemented\\n\", \\\n",
	filter_filename (instruction->line->file_name),
	instruction->line->line_nr);
	lf_printf (file, "(long) CIA, \\\n");
	lf_printf (file, "%sitable[MY_INDEX].name);\n",
	options.module.itable.prefix.l);
	lf_indent (file, -indent);
	lf_print__internal_ref (file);
	}

	/* Close off the conditional execution */
	if (filter_is_member (instruction->options, "c")
	\|\| options.gen.conditional_issue)
	{
	lf_indent (file, -4);
	lf_printf (file, " }\n");
	}
	}

	static void
	print_c_semantic (lf *file,
	const insn_entry *instruction,
	const opcode_bits *expanded_bits,
	const insn_opcodes *opcodes,
	cache_entry *cache_rules,
	int nr_prefetched_words)
	{

	lf_printf (file, "{\n");
	lf_indent (file, +2);

	print_my_defines (file,
	instruction->name,
	instruction->format_name, expanded_bits);
	lf_printf (file, "\n");
	print_icache_body (file,
	instruction,
	expanded_bits,
	cache_rules,
	(options.gen.direct_access
	? define_variables
	: declare_variables),
	(options.gen.icache
	? get_values_from_icache
	: do_not_use_icache), nr_prefetched_words);

	lf_printf (file, "%sinstruction_address nia;\n",
	options.module.global.prefix.l);
	print_semantic_body (file, instruction, expanded_bits, opcodes);
	lf_printf (file, "return nia;\n");

	/* generate something to clean up any #defines created for the cache */
	if (options.gen.direct_access)
	{
	print_icache_body (file,
	instruction,
	expanded_bits,
	cache_rules,
	undef_variables,
	(options.gen.icache
	? get_values_from_icache
	: do_not_use_icache), nr_prefetched_words);
	}

	lf_indent (file, -2);
	lf_printf (file, "}\n");
	}

	static void
	print_c_semantic_function (lf *file,
	const insn_entry *instruction,
	const opcode_bits *expanded_bits,
	const insn_opcodes *opcodes,
	cache_entry *cache_rules,
	int nr_prefetched_words)
	{
	/* build the semantic routine to execute the instruction */
	print_semantic_function_header (file,
	instruction->name,
	instruction->format_name,
	expanded_bits,
	1 /is-function-definition / ,
	nr_prefetched_words);
	print_c_semantic (file,
	instruction,
	expanded_bits, opcodes, cache_rules, nr_prefetched_words);
	}

	void
	print_semantic_definition (lf *file,
	const insn_entry *insn,
	const opcode_bits *expanded_bits,
	const insn_opcodes *opcodes,
	cache_entry *cache_rules,
	int nr_prefetched_words)
	{
	print_c_semantic_function (file,
	insn,
	expanded_bits,
	opcodes, cache_rules, nr_prefetched_words);
	}